限制Go堆接口实现的优先级队列的大小

type Item struct {
    priority int
    data     interface{}
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int {
    return len(pq)
}

func (pq PriorityQueue) Less(i, j int) bool {
    return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
    pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
    item := x.(*Item)
    *pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
    old := *pq
    n := len(old)
    item := old[n-1]
    *pq = old[0 : n-1]
    return item
}

func main() {
    pq := make(PriorityQueue, 0, 5) // 设置最大容量为5

    // 添加元素到队列中
    heap.Push(&pq, &Item{priority: 3, data: "data1"})
    heap.Push(&pq, &Item{priority: 1, data: "data2"})
    heap.Push(&pq, &Item{priority: 2, data: "data3"})
    heap.Push(&pq, &Item{priority: 5, data: "data4"})
    heap.Push(&pq, &Item{priority: 4, data: "data5"})

    // 遍历队列中的元素
    for pq.Len() > 0 {
        item := heap.Pop(&pq).(*Item)
        fmt.Printf("Priority: %d, Data: %s\n", item.priority, item.data)
    }
}

Priority: 1, Data: data2
Priority: 2, Data: data3
Priority: 3, Data: data1
Priority: 4, Data: data5
Priority: 5, Data: data4